1
|
Arumugam R, Fleenor D, Lu D, Freemark M. Differential and complementary effects of glucose and prolactin on islet DNA synthesis and gene expression. Endocrinology 2011; 152:856-68. [PMID: 21239441 PMCID: PMC3198965 DOI: 10.1210/en.2010-1258] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The mechanisms by which lactogenic hormones promote β-cell expansion remain poorly understood. Because prolactin (PRL) up-regulates β-cell glucose transporter 2, glucokinase, and pyruvate dehydrogenase activities, we reasoned that glucose availability might mediate or modulate the effects of PRL on β-cell mass. Here, we used male rat islets to show that PRL and glucose have differential but complementary effects on the expression of cell cyclins, cell cycle inhibitors, and various other genes known to regulate β-cell replication, including insulin receptor substrate 2, IGF-II, menin, forkhead box protein M1, tryptophan hydroxylase 1, and the PRL receptor. Differential effects on gene expression are associated with synergistic effects of glucose and PRL on islet DNA synthesis. The effects of PRL on gene expression are mirrored by β-cell overexpression of signal transducer and activator of transcription 5b and are opposed by dexamethasone. An ad-small interfering RNA specific for cyclin D2 attenuates markedly the effects of PRL on islet DNA synthesis. Our studies suggest a new paradigm for the control of β-cell mass and insulin production by hormones and nutrients. PRL up-regulates β-cell glucose uptake and utilization, whereas glucose increases islet PRL receptor expression and potentiates the effects of PRL on cell cycle gene expression and DNA synthesis. These findings suggest novel targets for prevention of neonatal glucose intolerance and gestational diabetes and may provide new insight into the pathogenesis of β-cell hyperplasia in obese subjects with insulin resistance.
Collapse
Affiliation(s)
- Ramamani Arumugam
- Duke University Medical Center, Department of Pediatrics, Durham, North Carolina 27710, USA
| | | | | | | |
Collapse
|
2
|
Alam SMK, Ain R, Konno T, Ho-Chen JK, Soares MJ. The rat prolactin gene family locus: species-specific gene family expansion. Mamm Genome 2006; 17:858-77. [PMID: 16897344 DOI: 10.1007/s00335-006-0010-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 03/28/2006] [Indexed: 01/22/2023]
Abstract
In the rat there is a large family of paralogous genes related to prolactin (PRL). Members of the PRL family are expressed in cell- and temporal-specific patterns in the anterior pituitary, uterus, and placenta. An overriding feature of the PRL family is its association with pregnancy. In this investigation, we used information derived from the public rat genome database as a tool for identifying new members of the rat PRL family. The entire rat PRL gene family locus spans approximately 1.7 megabases (Mb) on Chromosome 17. Genes possessed either 5- or 6-exon organization patterns. We provide information on three newly identified genes orthologous to previously identified members of the mouse PRL gene family [placental lactogen-Ialpha (PL-Ialpha), PL-Ibeta, and proliferin (PLF)] and a new member of the PRL family, termed PRL-like protein-P (PLP-P). Information is also presented on the existence of multiple PLP-M transcripts, which are generated by alternative splicing. Expansion of the PRL family has occurred independently in rodents versus the cow and does not exist in the human and dog. Elucidation of the rat PRL gene family locus provides tools for studying the genetics and biology of the rat PRL family and new insights into species-specific gene family expansion.
Collapse
Affiliation(s)
- S M Khorshed Alam
- Institute of Maternal-Fetal Biology and the Division of Cancer & Developmental Biology, Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | | | | | | | | |
Collapse
|
3
|
Abstract
In the mouse, there is a large family of paralogous genes closely related to PRL. The objective of this report was to investigate the organization of the mouse PRL gene family locus. PRL family genes reside on chromosome 13 of the mouse genome. The PRL gene family members were localized to a series of overlapping bacterial artificial chromosome clones and arranged based on structural relationships. Additionally, several new members of the PRL gene family were identified. Placental lactogen I (PL-I) was found to be encoded by three closely related (>98% exon sequence identity) contiguous genes (termed: PL-Ialpha, PL-Ibeta, and PL-Igamma). Two previously unidentified mouse orthologs for members of the rat PRL family, PRL-like protein-I (PLP-I) and PLP-K were discovered, as were two new members of the PLP-C subfamily, PLP-Cgamma and PLP-Cdelta, and two new entirely unique members of the PRL family, PLP-N and PLP-O. Amino acid sequences predicted from the latter two genes most closely resembled proliferin-related protein. Each of the nine newly discovered genes is expressed in trophoblast cells of the mouse placenta in a gestationally specific pattern. In summary, elucidation of the mouse PRL gene family locus provides new insights into the expansion of the mouse PRL family and new tools for studying the genetics and biology of its members.
Collapse
Affiliation(s)
- Dustin O Wiemers
- Institute of Maternal-Fetal Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | | | | | | | | |
Collapse
|
4
|
|
5
|
Freeman ME, Kanyicska B, Lerant A, Nagy G. Prolactin: structure, function, and regulation of secretion. Physiol Rev 2000; 80:1523-631. [PMID: 11015620 DOI: 10.1152/physrev.2000.80.4.1523] [Citation(s) in RCA: 1463] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Prolactin is a protein hormone of the anterior pituitary gland that was originally named for its ability to promote lactation in response to the suckling stimulus of hungry young mammals. We now know that prolactin is not as simple as originally described. Indeed, chemically, prolactin appears in a multiplicity of posttranslational forms ranging from size variants to chemical modifications such as phosphorylation or glycosylation. It is not only synthesized in the pituitary gland, as originally described, but also within the central nervous system, the immune system, the uterus and its associated tissues of conception, and even the mammary gland itself. Moreover, its biological actions are not limited solely to reproduction because it has been shown to control a variety of behaviors and even play a role in homeostasis. Prolactin-releasing stimuli not only include the nursing stimulus, but light, audition, olfaction, and stress can serve a stimulatory role. Finally, although it is well known that dopamine of hypothalamic origin provides inhibitory control over the secretion of prolactin, other factors within the brain, pituitary gland, and peripheral organs have been shown to inhibit or stimulate prolactin secretion as well. It is the purpose of this review to provide a comprehensive survey of our current understanding of prolactin's function and its regulation and to expose some of the controversies still existing.
Collapse
Affiliation(s)
- M E Freeman
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4340, USA.
| | | | | | | |
Collapse
|
6
|
Hiraoka Y, Ogawa M, Sakai Y, Takeuchi Y, Komatsu N, Shiozawa M, Tanabe K, Aiso S. PLP-I: a novel prolactin-like gene in rodents. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1447:291-7. [PMID: 10542329 DOI: 10.1016/s0167-4781(99)00160-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In this report, we describe molecular cloning and characterization of cDNAs encoding a novel rat prolactin-like protein. The rat cDNAs were isolated from the decidua and the gene was named PLP-I. cDNAs for the mouse equivalent were also cloned by the cross-hybridization technique. Pregnancy-specific expression of the rat PLP-I gene was observed in the rat placenta by Northern analysis. Location of signal peptide cleavage sites in rat and mouse pre-PLP-I proteins was predicted using a theoretical method. A molecular phylogenetic tree for the growth hormone-prolactin superfamily including the novel member, PLP-I, constructed using the neighbor-joining method, places rat/mouse PLP-I closest to rat/mouse placental lactogen I and II.
Collapse
Affiliation(s)
- Y Hiraoka
- Department of Anatomy, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Hirosawa-Takamori M, Matsruura Y, Tanaka S, Ogawa T, Shiota K. Characterization of Rat Mid-Pregnancy-Specific Placental Lactogen Produced by Baculovirus / Insect Cell Expression System. J Reprod Dev 1999. [DOI: 10.1262/jrd.45.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
| | | | - Satoshi Tanaka
- Animal Resource Science/Veterinary Medical Science, University of Tokyo, Tokyo 113-8657, Japan
| | - Tomoya Ogawa
- Animal Resource Science/Veterinary Medical Science, University of Tokyo, Tokyo 113-8657, Japan
| | - Kunio Shiota
- Animal Resource Science/Veterinary Medical Science, University of Tokyo, Tokyo 113-8657, Japan
| |
Collapse
|
8
|
Shah P, Sun Y, Szpirer C, Duckworth ML. Rat placental lactogen II gene: characterization of gene structure and placental-specific expression. Endocrinology 1998; 139:967-73. [PMID: 9492027 DOI: 10.1210/endo.139.3.5838] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Rat placental lactogen II (rPLII) was the first described member of the rat PRL-like placental gene family in which nine novel proteins have now been identified. In this article, we present data on the isolation and characterization of the rPLII gene. Two genomic clones, GC I (18.5 kb) and GC II (9.4 kb), were isolated from an EMBL3 Sprague-Dawley rat liver genomic DNA library. GC I, which was used for further analysis, contains the entire coding region and extensive 5' and 3' flanking information. The rPLII gene, estimated to be 5.4 kb in size, has the same five-exon and four-intron structure and identical intron/exon splice sites and types as the rPRL gene. A major transcription start site 58 bp upstream of the initiator methionine codon and several minor sites 1-3 bp 5' and 3' of this site were identified by primer extension of day 18 placental messenger RNA. The rPLII gene has been localized to chromosome 17, using a series of hybrid cell lines derived from mouse hepatoma cells (MWTG3) and adult rat hepatocytes; this is the same chromosome designation as the PRL gene itself and other cloned placental members of this gene family. Luciferase reporter constructs containing 5' flanking DNA sequences were tested in transient transfection assays in the rat choriocarcinoma cell line, Rcho, and the rat pituitary GC cell line. Both a 4.5- and 3-kb 5' flanking sequence supported luciferase expression in the Rcho but not the GC cells. A 765-bp fragment showed no activity in either cell type. Transient transgenic mice, generated with the 3-kb 5' rPLII/luciferase construct, expressed varying amounts of luciferase expression in the placenta.
Collapse
Affiliation(s)
- P Shah
- Department of Physiology, University of Manitoba, Winnipeg, Canada
| | | | | | | |
Collapse
|
9
|
Shiota K, Min KS, Miura R, Hirosawa M, Hattori N, Noda K, Ogawa T. Molecular diversity of rat placental lactogens. Placenta 1997. [DOI: 10.1016/s0143-4004(05)80156-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
10
|
Affiliation(s)
- M J Soares
- Department of Physiology, University of Kansas Medical Center, Kansas City 66160, USA
| | | | | | | | | | | |
Collapse
|
11
|
Cohick CB, Dai G, Xu L, Deb S, Kamei T, Levan G, Szpirer C, Szpirer J, Kwok SC, Soares MJ. Placental lactogen-I variant utilizes the prolactin receptor signaling pathway. Mol Cell Endocrinol 1996; 116:49-58. [PMID: 8822264 DOI: 10.1016/0303-7207(95)03695-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Placenta lactogen-I variant (PL-Iv) is a member of a family of proteins expressed by the rat placenta with characteristics similar to prolactin (PRL). In this report, we present the molecular cloning, chromosomal localization, and heterologous expression of PL-Iv. Nucleotide sequence analysis of the PL-Iv cDNA clone predicted a precursor protein of 223 amino acids, including a 28-amino acid signal sequence. The PL-Iv gene was localized to chromosome 17 of the rat genome, which also carries other members of the PRL gene family. PL-Iv heterologously expressed in Chinese Hamster ovary (CHO) cells exhibited similar immunoreactive and electrophoretic characteristics with PL-Iv produced by the rat placenta. N-terminal sequencing verified the identity and purity of the recombinant PL-Iv species and the site of cleavage of the signal peptide from the mature secreted PL-Iv species. Recombinant PL-Iv was shown to bind to ovarian and liver PRL receptors, stimulate the proliferation of Nb2 lymphoma cells, and activate Jak2. Each of these actions is consistent with PL-Iv utilizing the PRL receptor signal transduction pathway.
Collapse
Affiliation(s)
- C B Cohick
- Department of Physiology, University of Kansas Medical Center, Kansas City 66160-7401, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Conliffe PR, Simmen RC, Buhi WC, Shiverick KT. Cloning of a novel rat placental prolactin-like protein C-related cDNA. Mol Reprod Dev 1995; 41:167-76. [PMID: 7654370 DOI: 10.1002/mrd.1080410207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Prolactin-like protein C (PLP-C) is a major rat placental protein which is expressed during the second half of pregnancy and belongs to the growth hormone-prolactin family. Here we report on the isolation of overlapping rat placental cDNAs which specify a transcript of 915 base pairs and predict a 205-amino acid translated product. The full-length cDNA shares 93% homology with the nucleotide sequence reported for PLP-C, and the putative protein, which we designate PCRP (prolactin-like protein C-related protein), exhibits 88% homology with the PLP-C precursor protein. PCRP lacks the signal sequence and the first 2 N-terminal cysteine residues present in PLP-C. Northern blot analysis indicated the basal zone-specific expression of PCRP mRNA, with no detectable expression in decidua and labyrinth. Southern blot analysis of rat genomic DNA using PCRP cDNA as a probe demonstrated multiple hybridization bands, suggestive of a family of genes encoding prolactin-like proteins. Western immunoblot analysis of basal zone culture media using a PCRP antipeptide antiserum revealed at least 5 immunoreactive proteins. The existence of a PLP-C family of proteins in rat placenta after midpregnancy suggests their functional significance in the maintenance of pregnancy and fetal development.
Collapse
Affiliation(s)
- P R Conliffe
- Department of Pharmacology, University of Florida, Gainesville 32610, USA
| | | | | | | |
Collapse
|
13
|
MUTAI H, HATTORI N, KAMEI T, AIKAWA JI, SHIOTA K, OGAWA T. Prolactin Receptor mRNA Expression in Fetal Rat Brain. J Reprod Dev 1995. [DOI: 10.1262/jrd.41.353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Hideki MUTAI
- Laboratory of Cellular Biochemistry, Department of Veterinary Medical Sciences/Animal Resource Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113, Japan
| | - Naka HATTORI
- Laboratory of Cellular Biochemistry, Department of Veterinary Medical Sciences/Animal Resource Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113, Japan
| | - Takayuki KAMEI
- Department of Veterinary Physiology, Nippon Veterinary and Animal Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180, Japan
| | - Jun-ichi AIKAWA
- Laboratory of Synthetic Cellular Chemistry, Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01, Japan
| | - Kunio SHIOTA
- Laboratory of Cellular Biochemistry, Department of Veterinary Medical Sciences/Animal Resource Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113, Japan
| | - Tomoya OGAWA
- Laboratory of Cellular Biochemistry, Department of Veterinary Medical Sciences/Animal Resource Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113, Japan
- Laboratory of Synthetic Cellular Chemistry, Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-01, Japan
| |
Collapse
|
14
|
Conliffe PR, Farmerie WG, Charles GD, Buhi WC, Kelly PA, Simmen RC, Shiverick KT. Expression and characterization of recombinant rat placental prolactin-like protein C. Mol Cell Endocrinol 1994; 106:121-30. [PMID: 7895899 DOI: 10.1016/0303-7207(94)90193-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Prolactin-like protein C (PLP-C) is a member of the rat placental family of proteins which are structurally related to pituitary prolactin (PRL). In an effort to characterize the receptor specificity and biological activity of PLP-C, we used a PLP cDNA to express the recombinant protein in a bacterial system. The PLP-C cDNA was modified by oligonucleotide mutagenesis and ligated into a human carbonic anhydrase II (hCAII) expression vector. Following a single step affinity purification, the hCAII-PLP-C fusion protein was digested with enterokinase to release a 25 kDa protein. N-Terminal sequence analysis of the 25 kDa band demonstrated identity with PLP-C. A polyclonal antiserum to the fusion protein cross reacted with seven major proteins in rat placental culture media of which two were the native forms of PLP-C. Recombinant PLP-C was not mitogenic in the Nb2 lymphoma bioassay and did not exhibit high affinity binding to rat PRL receptor. The choice of hCA-II fusion allows for rapid purification of rPLP-C which will aid in further investigation of the biological role of PLP-C.
Collapse
Affiliation(s)
- P R Conliffe
- Department of Pharmacology, University of Florida College of Medicine, Gainesville 32610
| | | | | | | | | | | | | |
Collapse
|
15
|
Roby K, Deb S, Gibori G, Szpirer C, Levan G, Kwok S, Soares M. Decidual prolactin-related protein. Identification, molecular cloning, and characterization. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53669-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|